#include "vtor_modbus.h"

#ifdef __VTOR_MODBUS__

uint8_t vtorModbusId = 0x01;
VtorModbusRegStruct* vtorModbusRegisterHeader = NULL;

static uint16_t* requestRegBuf = NULL;
static uint16_t requestRegNum = 0;
static uint8_t modbusReplyBuf[50] = {0};

int16_t Host2Net16(int16_t val)
{
	val =  ((val & 0xff) << 8)
		| ((val & 0xff00) >> 8);
	return val;
}

uint8_t VtorModbus_ReadSlaveReg(uint8_t slaveId, uint16_t regAddr, uint16_t* regBuf, uint16_t regNum)
{
	// 调整从机的id与数据存放地址，稍后校验
	vtorModbusId = slaveId;
	requestRegBuf = regBuf;
	requestRegNum = regNum;
	// 开始封装
	VtorModbusRequestReadRegisterFrameStruct* reqFrame
		= (VtorModbusRequestReadRegisterFrameStruct*)modbusReplyBuf;
	reqFrame->id = slaveId;
	
	
	if (regAddr >= VTOR_MODBUS_RW_REG_START_ADDR
		&& regAddr <= VTOR_MODBUS_RW_REG_END_ADDR)
	{
		regAddr -= VTOR_MODBUS_RW_REG_START_ADDR;
		reqFrame->cmd = VTOR_MODBUS_FUNCTION_READ_HOLDING_REGISTER;
	}
	else if (regAddr >= VTOR_MODBUS_RO_REG_START_ADDR
		&& regAddr <= VTOR_MODBUS_RO_REG_END_ADDR)
	{
		regAddr -= VTOR_MODBUS_RO_REG_START_ADDR;
		reqFrame->cmd = VTOR_MODBUS_FUNCTION_READ_INPUT_REGISTER;
	}
	else
	{
		return 1;
	}
	reqFrame->regAddr = Host2Net16(regAddr);
	reqFrame->regNum = Host2Net16(regNum);
	VtorModbus_CheckCrc(modbusReplyBuf, 8);
	VtorModbus_SendBuffer(modbusReplyBuf, 8);
	return 0;
}

uint8_t VtorModbus_WriteSlaveReg(uint8_t slaveId, uint16_t regAddr, uint16_t* regBuf, uint16_t regNum)
{
	int16_t sendLen = 0;
	int16_t regIdx = 0;
	// 调整从机的id与数据存放地址，稍后校验
	vtorModbusId = slaveId;
	requestRegBuf = NULL;
	
	// 开始封装
	VtorModbusRequestWriteMultiInputRegisterFrameStruct* reqFrame
		= (VtorModbusRequestWriteMultiInputRegisterFrameStruct*)modbusReplyBuf;
	reqFrame->id = slaveId;
	
	
	if (regAddr >= VTOR_MODBUS_RW_REG_START_ADDR
		&& regAddr <= VTOR_MODBUS_RW_REG_END_ADDR)
	{
		regAddr -= VTOR_MODBUS_RW_REG_START_ADDR;
		reqFrame->cmd = VTOR_MODBUS_FUNCTION_WRITE_MULTIPLE_REGISTER;
	}
	else
	{
		return 1;
	}

	reqFrame->regAddr = Host2Net16(regAddr);
	reqFrame->regNum = Host2Net16(regNum);
	reqFrame->byteNum = regNum * 2;
	
	for(regIdx = 0; regIdx < regNum; regIdx++)
	{
		reqFrame->regData[regIdx] = regBuf[regIdx];
	}
	VtorModbus_CheckCrc(modbusReplyBuf, 7 + regNum * 2 + 2);
	VtorModbus_SendBuffer(modbusReplyBuf, 7 + regNum * 2 + 2);
	return 0;
}

uint8_t VtorModbus_ReadReg(uint16_t regAddr, uint16_t* regBuf, uint16_t regNum)
{
	int i = 0;
	struct VtorModbusRegister* reg = VtorModbus_SearchAddress(regAddr);
	if (NULL == reg)
	{
		return 1;
	}
	for (i = 0; i < regNum && reg->addr != 0; i++)
	{
		regBuf[i] = reg->value;
		reg++;
	}
	return 0;
}

uint8_t VtorModbus_WriteReg(uint16_t regAddr, uint16_t* regBuf, uint16_t regNum)
{
	int i = 0;
	struct VtorModbusRegister* reg = VtorModbus_SearchAddress(regAddr);
	if (NULL == reg)
	{
		return 1;
	}
	for (i = 0; i < regNum && reg->addr != 0; i++)
	{
		reg->value = regBuf[i];
		reg++;
	}
	return 0;
}

struct VtorModbusRegister* VtorModbus_SearchAddress(uint16_t addr)
{
	struct VtorModbusRegister* reg = vtorModbusRegisterHeader;
	while(0 != reg->addr)
	{
		if(reg->addr == addr)
		{
			return reg;
		}
		reg++;
	}
	return NULL;
}

#ifdef __VTOR_MODBUS_CONFIG_CRC_CALC__

uint8_t VtorModbus_CheckCrc(uint8_t* buf, uint16_t totalLen)
{
	//https://blog.csdn.net/qq_35358125/article/details/106296169
	uint16_t TCPCRC = 0xffff;
	uint16_t POLYNOMIAL = 0xa001;
	uint8_t i, j;
	uint16_t dataLen = totalLen - 2;
	for (i = 0; i < dataLen; i++)
	{
		TCPCRC ^= buf[i];
		for (j = 0; j < 8; j++)
		{
			if ((TCPCRC & 0x0001) != 0)
			{
				TCPCRC >>= 1;
				TCPCRC ^= POLYNOMIAL;
			}
			else
			{
				TCPCRC >>= 1;
			}
		}
	}
	// 如果crc错误，纠正，并返回1，此函数可同时校验和计算
	if ((buf[totalLen - 2] != (TCPCRC & 0xff))
	|| (buf[totalLen - 1] != TCPCRC >> 8))
	{
		buf[totalLen - 2] = TCPCRC & 0xff;
		buf[totalLen - 1] = TCPCRC >> 8;
		return 1;
	}
	return 0;
}

#endif

#ifdef __VTOR_MODBUS_CONFIG_CRC_NULL__

uint8_t VtorModbus_CheckCrc(uint8_t* buf, uint16_t totalLen)
{
	return 0;
}

#endif

#ifdef __VTOR_MODBUS_CONFIG_CRC_TABLE__

// https://blog.csdn.net/qq_35358125/article/details/106296169
//查表方式实现
static const uint8_t aucCRCHi[] = {
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40
};

static const uint8_t aucCRCLo[] = {
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7,
0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E,
0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9,
0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC,
0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32,
0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D,
0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38,
0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF,
0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1,
0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4,
0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB,
0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA,
0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0,
0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97,
0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E,
0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89,
0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83,
0x41, 0x81, 0x80, 0x40
};

uint8_t VtorModbus_CheckCrc(uint8_t* buf, uint16_t totalLen)
{
	uint8_t ucCRCHi = 0xFF;
	uint8_t ucCRCLo = 0xFF;
	int iIndex;

	uint16_t dataLen = totalLen - 2;
	while( dataLen-- )
	{
		iIndex = ucCRCLo ^ *( buf++ );
		ucCRCLo = ( uint8_t )( ucCRCHi ^ aucCRCHi[iIndex] );
		ucCRCHi = aucCRCLo[iIndex];
	}
	// 如果crc错误，纠正，并返回1，此函数可同时校验和计算
	if ((*buf != ucCRCLo)
		|| (*(buf+1) != ucCRCHi))
	{
		*buf++ = ucCRCLo;
		*buf++ = ucCRCHi;
		return 1;
	}
	return 0;
}

#endif

uint16_t VtorModbusMaster_Process(uint8_t* rxBuf, uint16_t len)
{
	uint8_t i = 0;
	uint8_t id = rxBuf[0];
	uint8_t cmd = rxBuf[1];
	uint16_t byteNum = rxBuf[2];
	if(len < 6)
	{
		return 3;
	}
	if(vtorModbusId != id && id != 0)
	{
		return 2;
	}
	if (VtorModbus_CheckCrc(rxBuf, len))
	{
		return 1;
	}
	// 写数据时只需要保证crc没问题就行
	// 因此需要对读数据进行处理，并进行赋值
	if(byteNum != requestRegNum * 2)
	{
		return 4;
	}
	if (cmd == 0x03 || cmd == 0x04)
	{
		for(i = 0; i < requestRegNum; i++)
		{
			requestRegBuf[i] = (rxBuf[3 + i * 2] << 8) | rxBuf[4 + i * 2];
		}
		// 数据获取完成，将其指向空
		requestRegNum = 0;
		requestRegBuf = NULL;
	}
	return 0;
}

uint16_t VtorModbusSlave_Process(uint8_t* rxBuf, uint16_t len)
{
	uint16_t replyLen = 0, j = 0;
	uint8_t id = rxBuf[0];
	uint8_t cmd = rxBuf[1];
	uint16_t regAddr = rxBuf[2] << 8 | rxBuf[3];
	uint16_t regNum = rxBuf[4] << 8 | rxBuf[5];
	struct VtorModbusRegister* reg = NULL;

	if(len < 6)
	{
		return 3;
	}
	if (VtorModbus_CheckCrc(rxBuf, len))
	{
		return 1;
	}
	if(vtorModbusId != id && id != 0)
	{
		return 2;
	}
	if (cmd == 0x03 || cmd == 0x06 || cmd == 0x10)
	{
		regAddr += 40001;
	}
	else if (cmd == 0x04)
	{
		regAddr += 30001;
	}
	else
	{
		return 3;
	}

	reg = VtorModbus_SearchAddress(regAddr);
	if(NULL == reg)
	{
		return 4;
	}


	modbusReplyBuf[replyLen++] = vtorModbusId; // 返回时使用自己的id
	modbusReplyBuf[replyLen++] = rxBuf[1]; // 功能码
	if (cmd == 0x03 || cmd == 0x04)
	{
		modbusReplyBuf[replyLen++] = 2 * regNum;
		for(j = 0; j < regNum && reg->addr != 0; j++)
		{
			modbusReplyBuf[replyLen++] = reg->value >> 8;
			modbusReplyBuf[replyLen++] = reg->value & 0xff;
			reg++;
		}
	}
	else if (cmd == 0x06)
	{
		regNum = 1;
		modbusReplyBuf[replyLen++] = rxBuf[2];
		modbusReplyBuf[replyLen++] = rxBuf[3];

		reg->value = rxBuf[4] << 8 | rxBuf[5];
		modbusReplyBuf[replyLen++] = reg->value >> 8;
		modbusReplyBuf[replyLen++] = reg->value & 0xff;
	}
	else if (cmd == 0x10)
	{
	  // 起始地址与长度信息
		modbusReplyBuf[replyLen++] = rxBuf[2]; // 寄存器首地址
		modbusReplyBuf[replyLen++] = rxBuf[3];
		modbusReplyBuf[replyLen++] = rxBuf[4]; // 寄存器个数
		modbusReplyBuf[replyLen++] = rxBuf[5];
		
		regNum = rxBuf[4] << 8 | rxBuf[5];

		for(j = 0; j < regNum && reg->addr != 0; j++)
		{
			reg->value = rxBuf[7 + j * 2] << 8 | rxBuf[7 + j * 2 + 1];
			reg++;
		}

	}
	VtorModbus_CheckCrc(modbusReplyBuf, replyLen + 2);
	VtorModbus_SendBuffer(modbusReplyBuf, replyLen + 2);
	return 0;
}


#endif // __VTOR_MODBUS__
